Staff: Mentor

In what context? Do you mean like tension in a rope? That's just the force being applied to one end of the rope, which shows up as tension all along the length of the rope to some anchor point. Maybe there's a more technical definition, given some context?

imagine a horizontal shaft for example.....now take any section in it.....now when the forces r such that they act away from each other in that particular section then the shaft is said to be in tension and the forces r called tensile or simply tension forces...
and compression forces r vice versa....get the picture????

So the definition of simple tension is that the forces are acting away from each other in a member